This invention relates to apparatus for fastening a safety belt to the door of a vehicle, and particularly to such apparatus, which is arranged to engage the column of the vehicle upon closing of the door, so that forces on the safety belt may be applied to the vehicle column as well as the frame of the door.
Prior U.S. Pat. No. 3,836,172, which is assigned to the same assignee as the present invention, discloses a safety belt fastening apparatus which includes a retaining bolt provided with an enlarged collar which engages a corresponding slot in a plate mounted to the vehicle door column. When the door is closed, forces applied to the safety belt are coupled to the vehicle column by means of the collar on the retaining bolt.
One problem with the prior arrangement, using a collar bolt, is that a relatively small force transmitting area exists between the bolt collar and the plate attached to the vehicle column. In addition, large structural tolerances associated with the vehicle door mounting must be overcome in aligning the retaining bolt with the corresponding slot in the plate attached to the door. A small change in the level of the vehicle door relative to the vehicle column can cause the retaining bolt to strike the retaining plate. Another problem with this arrangement is that during operation of the vehicle any vibration of the vehicle door with respect to the vehicle column will cause the retaining bolt to strike the sides of the slot in which it is engaged causing undesirable noise during the operation of the vehicle.
It is therefore an object of the present invention to provide a new and improved design for a safety belt fastening apparatus, wherein there is provided a larger force transfer area between the belt retaining member and the plate attached to the vehicle column.
It is another object of the invention to provide such an apparatus which can accommodate larger tolerances in the alignment of the vehicle door and will eliminate undesired rattling noises, which may occur during the operation of the vehicle.